In conventional refineries, fluid catalytic cracking (FCC) is the key process used to convert heavy distillates (vacuum gas oil) into transportation fuels such as gasoline, jet fuel, and diesel. Packed bed hydrotreating and hydroprocessing units are used for removing contaminants and enhancing the feedstock processability prior to further processing. For the past 30 years, tremendous advances have been achieved in FCC and packed bed hydrotreating/hydroprocessing technologies. Some of the improvements to these catalytic refinery processes have been made to their ability to process heavier feedstock, which typically comprises a blend of distillates and certain amount of residua. Currently, many modern refineries are equipped with resid fluid catalytic cracking (RFCC) units and packed bed resid hydroprocessing units to process and convert low-value heavy feedstock into transportation fuels. However, these catalytic processes require stringent feedstock quality specifications to prevent rapid catalyst deactivation and plugging of the catalyst-comprising packed bed. In particular, it has been generally believed that feedstocks with excessive Conradson Carbon Residue (CCR), and/or excessive total metals, would be unsuitable for processing through catalyst material-comprising packed beds. Zuo [Zuo, L., Technology-Economics in Petrochemical, Sinopec Technology and Economic Information Center, 2000, 16(1), 16-21] and Motaghi et al. [Motaghi, M., Subramanian, A. and Ulrich, B., Hydrocarbon Processing, Feb. 1, 2011, p. 37-43] suggest that, for RFCC, CCR content should not exceed eight (8) weight percent, based on the total weight of the feedstock, and 20 units of weight of total metals per million units of weight of feedstock. Dai et al. [Dai, L., Hu, Y. and Li, J., Petroleum Processing and Petrochemicals, 2000, 31(12), 13-16] and Threlkel et al. [Threlkel, R., Dillon, C., Singh, U. G. and Ziebarth, M. S., Proceedings of Japan Petroleum Institute International Symposium, Nov. 5-7, 2008] suggest that, for packed bed resid hydroprocessing, CCR content should not exceed 12 weight percent, based on the total weight of feedstock, and 100 units of weight of total metals per million units of weight of feedstock.
In this respect, it is generally believed that feedstocks with excessive CCR content, or excessive total metals content, are unsuitable for processing through catalytic material-comprising packed beds [Motaghi, M., Subramanian, A. and Ulrich, B., Hydrocarbon Processing, Feb. 1, 2011, p. 37-43]. Even after subjecting such feedstock to deasphalting, the resultant deasphalted heavy hydrocarbon-comprising material may still be unsuitable for processing through catalytic material-comprising packed beds, and often requires blending with light crude or a lighter hydrocarbon fraction so as to sufficiently dilute the undesirable contaminants to satisfactory concentrations for such processing [de Haan, D. Street, M. and Orzeszko, G., Hydrocarbon Processing, Feb. 1, 2013, p. 41-44].